A finite element analysis for asymmetric contraction after coiling of hot-rolled steel

Asymmetric contraction during natural cooling is often observed after the coiling of hot-rolled steel, which has significantly large hardenability due to high content of carbon or other alloying elements. In this study, a finite element (FE) model incorporating transformation plasticity was used to analyze the thermo-mechanical and metallurgical behavior of hot-rolled steel during the phase transformation after coiling. The transformation plasticity was caused by a small amount of stress that develops naturally in a hot-rolled coil due to the gravity. The asymmetric contraction behavior of the coil was reproduced successfully using the FE simulation by considering the transformation plasticity. The effect of some selected process variables on the asymmetric contraction was examined through a series of process simulations.